Active contours are now established as a technique for extracting salient contours from an image. Unfortunately the original technique suffers from many problems. A novel model-based dual active contour, a method of integrating global shape information with two active contours, has been developed to overcome the primary problems; sensitivity to initialisation and undesirable attractions by insignificant localised or regionalised features. The model guides the technique to avoid insignificant minima and is relinquished when the energy minimum is sufficiently compatible. The technique then finally operates as a pair of conventional active contours, ensuring that only image information is extracted, consistent with the original technique.